Question for ya, OP... What's the ballistic coefficienteny of a 556 69 gr bullet with a 1 and 9 twist?

Quoting: Southern Lighthouse

BC has nothing to do with the barrel twist. bullet mfr is also necessary to know the exact BC...along with the type of bullet..

Quoting: Anonymous Coward 17785333

Most .223 or 55.6 barrels are a 1 - 7 twist. You cant fire a 69 Gr bullet in a 1-7 twist Barrel.

Quoting: USMC0369

69 gr Federal SMK work VERY well from all 1/9 twist COLT barrels in the early 1990's....Military HiPower Comp.YES YOU CAN........Back up just a bit. 55 gr is fine in most 1/7 twist 16" or shorter guns....MOST......depends on bullet construction. I know my Guns. Wrong.